Environment as a complex system consists of elements formed and changed throughout the time in accordance with its structure and development characteristics. These changes led to gradual transformation of the physical elements of environment; and consequently have shaped and caused the new environmental landscape. Characteristics of these changes can be studied in a meaningful way through understanding environmental patterns; within which influential causes and factors will be identified and analyzed. This paper therefore, aims to investigate and analyze the landscape and environmental changes in the Daarabad Valley- Tehran in the forty five years (1956-2001) period. With its considerable role and implication in the analysis of complex systems, the Chaos theory was used as new approach to develop a theoretical framework for analyzing Daarabad valley's environmental changes. Image Classification and Texture Analysis are recognized as useful techniques in the process of tracking environmental and landscape changes in recent decades. Therefore, the Daarabad valley aerial photographs were used and analyzed through “IMAGE PROCESSING” method. Through a mathematical algorithm based on GABOR filter in MATLAB environment. This provided a medium for the Pattern Recognition and analysis of environmental changes in the area. Research findings of this paper demonstrate that characteristics of landscape and environmental elements such as floral pattern (plants covering, native plants, and gardens), city form and open space are changing continuously during the time. Therefore, growth or change of these patterns are generally unpredictable; even tough, to some extent a fractal pattern of development might be observed. This might suggest considering the concept of uncertainty as a major issue in the field of environmental design and urban/regional planning.